clinical heterogeneity, but early death from cachexia and dementia, early cutaneous tumors and atherosclerosis.

Cytogenetics

Inborn conditions

as in XP, the UV ligth-induced level of sister chromatid exchange (SCE) is increased as well as the rate of chromosome aberrations, mainly chromatid breaks

Genes involved and Proteins

Note

There is genetic heterogeneity in CS, giving rise to complementation groups

the genes involved are: CSA, also called ERCC8 (ERCC for Excision-Repair Cross Complementing rodent repair deficiency) located on chromosome 5, CSB, also called ERCC6 , located in 10q11-21; outside CSA and CSB, there is: 3 patients who are XPB/CS, involving XPB, also called ERCC3, located in 2q21; 2 patients XPD/CS, involving XPD, also called ERCC2, located in 19q13; and 6 patients XPG/CS, involving XPG, also called ERCC5, located in 13q32 (note: the class of patients with both XP and CS were classified earlier as CS III, but not anymore).